[CPUFREQ] Add p4-clockmod ->get

p4-clockmod is a bit more complicated as it might run on SMP, HT, and
the instructions need to run on the specific (physical) CPU.

arch/i386/kernel/cpu/cpufreq/p4-clockmod.c

@@ -252,6 +252,43 @@ static int cpufreq_p4_cpu_exit(struct cpufreq_policy *policy)
 	return 0;
 }
 
+static unsigned int cpufreq_p4_get(unsigned int cpu)
+{
+	unsigned int hyperthreading;
+	cpumask_t cpus_allowed, affected_cpu_map;
+	u32 l, h;
+
+	hyperthreading = 0;
+
+	/* only run on CPU to be set, or on its sibling */
+	cpus_allowed = current->cpus_allowed;
+	affected_cpu_map = cpumask_of_cpu(cpu);
+#ifdef CONFIG_X86_HT
+	hyperthreading = ((cpu_has_ht) && (smp_num_siblings == 2));
+	if (hyperthreading) {
+		sibling = cpu_sibling_map[cpu];
+		cpu_set(sibling, affected_cpu_map);
+	}
+#endif
+	set_cpus_allowed(current, affected_cpu_map);
+        BUG_ON(!cpu_isset(smp_processor_id(), affected_cpu_map));
+
+	rdmsr(MSR_IA32_THERM_CONTROL, l, h);
+
+	set_cpus_allowed(current, cpus_allowed);
+
+	if (l & 0x10) {
+		l = l >> 1;
+		l &= 0x7;
+	} else
+		l = DC_DISABLE;
+
+	if (l != DC_DISABLE)
+		return (stock_freq * l / 8);
+
+	return stock_freq;
+}
+
 static struct freq_attr* p4clockmod_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
 	NULL,
@@ -262,6 +299,7 @@ static struct cpufreq_driver p4clockmod_driver = {
 	.target		= cpufreq_p4_target,
 	.init		= cpufreq_p4_cpu_init,
 	.exit		= cpufreq_p4_cpu_exit,
+	.get		= cpufreq_p4_get,
 	.name		= "p4-clockmod",
 	.owner		= THIS_MODULE,
 	.attr		= p4clockmod_attr,